Pneumatic action for musical instruments.



N'o 821, 568. PATENTED MAY 22, 1906.

v F. w. WOOD. I P'NIEUMATIGQAGIION FOR'MUSIOAL INSTRUMBNTS.

APPLIOATION FILED JUNE 13. 1905- I [jig/ A? 4 {65 5 9 /0 6 l I I I Urrrran ears FREDERICK W. WOOD, OF KANSAS UITY .,MISSOURI.

PNEUMATEC ACT'ZON FOR .MUSICAL lNSTRUlVlENTS.

' Specification of Letters Patent.

Patented May 22, 1906.

Application fil d June 13,1905. seen No. 2e5,111.'

a citizen of the United States, residing'at Kansas City, in the county of Jackson and State of Missouri, have invented certain new and useful Improvements 1n Pneumatic Actions for Musical Instruments, of which the following is a specification.

This invention relates to pneumatic actions for musical instruments, and has for its object to produce a diaphragm construction which .operates noiselessly under the impact of the valve which cuts off communication between the chamber.

A further object is to producea diaphragm construction which guards against anypossibility of air-leakage following the action of pneumatics and the 'exh ustthe valve above referred to. V

A still further object is to produce a diaphragm ,construction which is less expensive in its construction and maintenance than that commonly employed in pneumatic actions for what are known as automatic pianos or piano-players.

To these ends the invention consists in certain novel and peculiar features of construction and combination of parts, as hereinafter described and claimed, and in order that it may be fully understood referenceis to be had to .the' accompanying drawings, in which Figure 1 is a,top lan view of the pneumatic action with t at portion superposed with relation to the exhaust-chamber omitted, said figure showing two diaphragm structuresone complete and the other with the diaphragm proper and block carried:

thereby omitted. Fig. 2 is a vertical section on'the line H II of Fig. 1, but difierent from the latter by showing the diaphragm proper and. the block carried thereby. Fig. is a detail perspective view of the removable diaphragm construction. 7

Referring now to the drawings in detail, 1 indicates the bottom board of the pneumaticaction mechanism; 2, the pneumatics underlying the same; 3, the passages leading from the pneumatics and adapted to connect I through. the valve-chambers (not shown) in the ottom board) and connecte with the exhaust-chamber 4. I

5 re resents passages (one only a peering at their duter ends by tubes 6 to the tracker-bar,

i ';(not shown,) each passage 5 being provided with a fine artitiom'ng-screen 7 to exclude from the va ve mechanism (not shown) any into the tracker-bar, and connecting each pas sage 5 with the exhaust-chamber between the screen and diaphragm is a vent-passage 8.

9 indicates blocks secured by screws 10 upon the bottom of the exhaust-chamber, a thin packingstrip 11, .secured by preference to the bottom of the block, making the connection of said block'with the bottom of the exhaust-chamber air-tight around passage 5.

which extends through said packing-strip 1 1 and communicates with passage 5. The block is also provided with a recess 12 in its upper side, and secured in any suitable manner upon the base of said recess is a cushion 13,.having a central aperture 14 forming a continuation of perforation 11 15 indicates a diaphragm of rubber, bridging the recess of the block and covering its upper side at opposite ends of the recess, as at 16, and its sides, as at 17, said diaphra m being secured to the block in any suita le manner, so as to make an air-tight connection therewith, the screws 10 also extending curing the same to the block.

18 is a block secured to the u per side of the diaphragm by elastic material and 19 is a sound-deadening cap secured to the top of the block, said cap being preferably of leather and adapted to receive the impact of the valve-stem (not shown) when the valve descends to close communication between its pneumatic and the exhaust-chamber. Commonly in pneumatic-action mechanism the diaphragm is in the form of a strip of rubber, extending the full length of the exhaustchamber and bridging cavities in the bottom thereof vertically above each passage 5, and should the diaphragm leak at any point it is necessary toremove it and in so doing to also remove other superposed arts which serve to hold it in position. Vi ith my improved diaphragm construction it will be seen that there is a separate and distinct diaphragm for each passage 5, and if it is found that any diaphragm is defective it can be guickly and easily removed by simply with- Said block has a central perforation 11*,

small foreign particles which may be drawn through the diaphragm, so as to assist in sei block remove the diaphragm proper, 15, from the 9 and equip the latter with a new one.

hen the valve depresses the diaphragm, as shown in Fig. 2, the cushion 13 makes the impact of block 18 noiseless, and, furthermore, permits said block to seat itself so snugly that leakage of air between the cushion and that portion of its diaphragm proper underlying the block is impossible, and it will also be noticed because the sharp edges of the block are rounded there is no appreciable wear on the diaphragm to shorten its period of service. v

From the above descri tion it will be apparent that I have prod iiced a pneumatic action for musical instruments possessing the features of advantage enumerated as desirable and which obviously is susceptible of modification without departing from the principle of construction involved.

Having thus described the invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A device for use in pneumatic actions for musical instruments, comprising a block having a central perforation and a recess, the latter being the full width of but terminating short of the ends of the block and com'munieating centrally with said perforation, and a diaphragm bridging said recess and secured at its ends to the ends of the block and at its sides to the side edges of the block and forming a chamber between it and the upper side of the block, which is air-tight except through the perforation of the latter.

2. A device for use in pneumatic actions for musical instruments, comp ising a block having a central perforation and a recess, the latter being the full width of but terminating short of the ends of the block and communicating centrally with'said perforation, a diaphragm bridging said recess and secured at its ends to the ends of the block and at its sides to the side edges of the block and forming a chamber between it. and the upper side of the block, which is air-tight except through the perforation of the latter, and a block secured to the upper side of the diaphragm and capable with the latter of sinking into the recess of the first-named block.

In testimony whereof I af fix my signature in the presence of two witnesses.

FREDERICK W. WOOD.

WVitnesses:

H. O. Ronenns, G. Y. THORPE. 

